1. Field of the Invention
This invention relates to a liquid transfer member pressing force adjusting method and apparatus of a rotary stencil printing plate liquid coating machine such as a rotary screen printing press. In the descriptions to follow, examples, in which a rotary screen printing press is used as a rotary stencil printing plate liquid coating machine, and ink is used as a liquid to be coated on a material to be liquid coated, will be explained to facilitate understanding. It goes without saying, however, that the present invention is similarly applied to a liquid coating machine using a stencil printing plate put to other uses instead of the rotary screen printing press, the liquid coating machine using a rotary screen coater for coating varnish in place of ink. Furthermore, the examples using a machine for coating the liquid on a sheet as the rotary stencil printing plate liquid coating machine will be explained. Needless to say, however, the present invention is similarly applied to a machine for coating the liquid on a web. If the liquid is coated on the web, a pressing roll without a notch for accommodating a gripper is used as a pressing body opposing a stencil printing plate cylinder, instead of an impression cylinder to be described below.
2. Description of the Related Art
A rotary screen printing press equipped with a squeegee or a doctor roller (ink transfer member=liquid transfer member), which is located within a rotary screen cylinder (stencil printing plate cylinder) and, during printing (liquid coating), is brought into contact with the inner peripheral surface of a screen printing forme (stencil printing plate), while being pressed against it, to transfer ink (liquid) stored within the rotary screen cylinder to a material to be printed (material to be liquid coated) supplied between the rotary screen cylinder and an impression cylinder through the holes of the screen printing forme, is generally well known.
With the conventional rotary screen printing press described above, an operator manually adjusts the pressing force of the squeegee or doctor roller acting on the inner peripheral surface of the screen printing forme in the rotary screen cylinder while printing.
Thus, the operator is burdened, and time is taken until normal printing products can be obtained by printing. Consequently, the rate of operation decreases and, during this process, a large amount of wasted paper occurs.
The present invention has been accomplished in light of the above-described problems. It is an object of the invention to provide a liquid transfer member pressing force adjusting method and apparatus of a rotary stencil printing plate liquid coating machine, which can lessen burden on the operator, increase the rate of operation, and curtail the occurrence of wasted paper.